You wouldn’t ordinarily think a 6-4 team sitting atop its division, albeit in a tie, would have some real serious problems.

But the Giants do. They’re on the descent, an annual ritual among faithful watchers of Big Blue. And it’s their own fault.

As Dallas remains on the ascent, the Giants have now lost two straight thanks to Sunday’s 17-10 home setback to the banged-up Eagles. It was a game they had to win, since tough New Orleans and incredibly potent Green Bay are served up next on the schedule. If the Giants intend to continue their first-half antics against those two, you might as well put them down for two losses and a 6-6 record right now.

You want to know why the Giants lost a game they really needed to win, and could have and should have won? To quote Sesame Street, this loss was brought to you by the Number 3.

Three measly points in the first half. Want another stat? In the last four games, the Giants have scored just 19 first-half points.

Teams can’t win games like that, even ones that have a fourth-quarter master like Eli Manning at the helm. Manning couldn’t pull off a comeback last week in San Francisco. And he couldn’t pull one off here, either, thanks to Jason Babin’s strip sack and fumble recovery with 1:17 remaining. That came only a minute and change after a defense that had done an overall great job shutting down LeSean McCoy and backup quarterback Vince Young inexplicably gave up an 18-play touchdown drive that consumed nearly nine minutes of the fourth quarter.

Young converted five third-down conversions, and then put a bow on it with an 8-yard scoring pass to Riley Cooper on third-and-9.

Fourth-quarter magic doesn’t always happen. Maybe the Giants are learning about that now. Hopefully, they’ve learned more than that. Perhaps they learned a lesson about keeping a struggling team absent starting quarterback Michael Vick and one of their top wide receivers in Jeremy Maclin in the game until the end.

Bad things can happen like that, and they did to the Giants in the Meadowlands.

As weak as the offense was, it wasn’t ALL their fault. If someone can explain why Steve Weatherford, not to be mistaken with Matt Dodge, punted directly to DeSean Jackson with 1:30 remaining in the first half to set up a Steve Smith touchdown and a 10-0 lead, please feel free. Granted, Weatherford was not around for last year’s catastrope, or the return Jackson made on Jeff Feagles to cost the Giants a game a few years ago.

But there are such things as history books. Past stats. Play-by-plays. Perhaps Weatherford, who should have known better, might have thought kicking it out of bounds was the better way to go in that situation.

And then there’s the defense, which did a good job all game long against McCoy despite the absence of veteran linebacker Michael Boley. Mathias Kiwanuka picked up the slack for him, and young backers Jacquian Williams and Mark Herzlich did a fine job clogging up the run.

But when it came to the fourth quarter, everything collapsed. The defensive backs, which picked Young three times, couldn’t make a play as the Eagles labored downfield from their 20. Eighteen plays. Inexcusable.

Despite that, go back to the first half.

Three points.

Five three-and-outs, including four straight.

Do that enough, and bad things are bound to happen.

Now that the Giants’ fourth-quarter magic seems to have dissipated, they’d better concentrate on faster starts.